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X-ray characterization technique for the assessment of surface damage in GaN wafers.
- Source :
-
Journal of Crystal Growth . Nov2018, Vol. 501, p13-17. 5p. - Publication Year :
- 2018
-
Abstract
- Highlights • 2 in. GaN crystals and wafers were produced by ammonothermal method. • X-ray characterization method suggested to check surface and subsurface damage. • (1 1 4) X-ray rocking curves measurements for each step of back-end processing. • Lack of uniformity of surface damage from different companies and from sample to sample. Abstract SixPoint Materials has successfully switched to production of two-inch diameter GaN wafers using the ammonothermal method. Crystal quality values are high with dislocation densities typically in the low 105 cm−2. In efforts to produce true epi-ready material, investigations were made to develop a technique to study surface damage caused by the back-end process using X-ray diffraction methods. Analysis of peak tailing from X-ray rocking curves of the (1 1 4) reflection indicates the progression of surface damage during each step of the back-end process. For instance, the tailing can be partially represented using full width five thousand max (FW5000M) values. By using a peak with a low glancing angle, such as the (1 1 4) reflection's angle of 10.8662°, more of the X-ray beam is scattered in the surface region, providing an improved measurement of surface damage. Since this technique is non-destructive and can be performed without dismounting the sample from its ceramic back-end processing plate, it can provide information on the damaged layer at each stage of the back-end process. Using this technique to evaluate samples from various manufacturers, we found a lack of uniformity in surface damage from GaN companies. It is our hope that this technique will be adopted to better standardize surface damage measurements in the GaN field. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00220248
- Volume :
- 501
- Database :
- Academic Search Index
- Journal :
- Journal of Crystal Growth
- Publication Type :
- Academic Journal
- Accession number :
- 131848049
- Full Text :
- https://doi.org/10.1016/j.jcrysgro.2018.08.025